[A case of traumatic spinal subarachnoid hematoma causing compression of the cauda equina]

A case of traumatic spinal subarachnoid hematoma causing compression of the cauda equina is reported here. The patient, a 76 year-old woman, who had fallen down by accident 1 month before, was admitted to our hospital presenting lumbar pain radiating into her right thigh, monoplegia of the right leg and urinary incontinence. Myelography and metrizamide CT demonstrated a filling defect mimicking intradural extramedullary tumor at the level of L1 and L2. Magnetic resonance imagings (MRI) revealed a subacute or chronic hematoma compressing the conus medullaris and the cauda equina. Operation was performed and an old hematoma, which occupied most of the spinal subarachnoid space and compressed the conus and cauda equina from right to left, was removed. No definite bleeding point was detected and no traumatic change was seen on the cord. Neither tumor nor abnormal vessel was detected. After surgery, the symptoms improved partially. On a review of the literature, we found only 4 cases of traumatic spinal subarachnoid hematoma, all of which occupied the cervical or thoracic portion of the spine. Our case is the first report, except for the cases following lumbar spinal tap, of traumatic spinal subarachnoid hematoma causing compression of the cauda equina. Though usually blood in CSF diffuses immediately, a clot may be formed when a large amount of bleeding obstructs the spinal canal. In our case, furthermore, deformity and narrowing of the spinal canal had preceded for many years, following lumbar vertebral compressed fracture related with osteoporosis. This might have promoted the process of canal obstruction and clot formation.(ABSTRACT TRUNCATED AT 250 WORDS)